Molded fibers

ABSTRACT

In accordance with embodiments of the present disclosure, the present invention is directed to improvements to molded fiber products. A first sealant layer can be applied to a prepressed biodegradable molded fiber or to biodegradable molded fiber which has not been prepressed. After the sealant layer has been applied, a heat press process is applied. A biodegradable paint can be applied to the first sealant layer. A sealer or binder can be mixed with paint before it is applied to the first sealant layer. A second sealant layer can be applied to the paint layer. Any binder mixed with the paint, as well as the first and second sealant layers respectively can comprise a natural, synthetic, oil based, or biodegradable polymer sealant, or a combination thereof. Preferably, the first sealant layer, the paint layer, and the second sealant layer add less than 10% of total non-biodegradable weight to the total weight of the molded fiber product.

RELATED APPLICATION

The present disclosure claims priority to U.S. Provisional Patent Application Ser. No. 62/380,697, filed Aug. 29, 2016, which is incorporated by reference herein in its entirety.

FIELD OF DISCLOSURE

The present invention pertains generally to improvements to molded fibers. More particularly, the present invention pertains to addressing the various issues encountered with the preparation and use of molded fibers, especially in packaging products.

BACKGROUND

Molded fiber material and processing is used to provide a biodegradable solution in place of synthetic and oil based material products. One application of molded fiber material is packaging material, such as a biodegradable egg carton or biodegradable packaging for consumer products. Currently, low cost molded fibers are mostly brown in color (e.g., virgin and recycled pulp). More expensive pulp and fiber based material, like A4 paper, bamboo, bagasse, a combination of bamboo and bagasse, wood, and paper foam are needed to provide white and/or other color fiber. However, most white and colored pulp have color fasting problems (e.g., shedding particles).

The present invention is directed to solving the deficiency in the prior art pertaining to the availability of high quality molded fiber. For example, the present invention is directed to providing molded fiber in different colors as well as molded fiber which may be multicolored. The present invention is also directed to providing a painted molded fiber that eliminates lifted fiber on the surface after painting. The present invention is further directed to eliminating the shedding of brown fiber and naturally colored molded fiber base material. The present invention is further directed to providing a painted molded fiber having reduced cracking and minimal to zero fasting issues. It is desirable that the colored surface of a painted fiber base material be greater than 90% biodegradable.

SUMMARY

In accordance with the teachings of the present disclosure, one or more disadvantages and problems associated with existing molded fibers may be reduced or eliminated.

In accordance with embodiments of the present disclosure, the present invention is directed to improvements to molded fiber products. A first sealant layer can be applied to a prepressed biodegradable molded fiber or to biodegradable molded fiber which has not been prepressed. After the sealant layer has been applied, a heat press process is applied. A biodegradable paint can be applied to the first sealant layer. The biodegradable paint can coat the surface of the molded fiber, with the first sealant layer, and provide unlimited color options, including multiple colors on the same molded fiber product. A sealer or binder can be mixed with paint before it is applied to the first sealant layer. A second sealant layer can be applied to the paint layer. Any binder mixed with the paint, as well as the first and second sealant layers respectively can comprise a natural, synthetic, oil based, or biodegradable polymer sealant, or a combination thereof. Preferably, the first sealant layer, the paint layer, and the second sealant layer add less than 10% of total non-biodegradable weight to the total weight of the molded fiber product.

Technical advantages of the present disclosure may be readily apparent to one skilled in the art from the figures, description and claims included herein. The objects and advantages of the embodiments will be realized and achieved at least by the elements, features, and combinations particularly pointed out in the claims.

It is to be understood that both the foregoing general description and the following detailed description are examples and explanatory and are not restrictive of the claims set forth in this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein:

FIG. 1 illustrates a cross-section of an improved molded fiber, in accordance with embodiments of the present disclosure;

FIG. 2 illustrates a cross-section of an improved molded fiber, in accordance with embodiments of the present disclosure; and

FIG. 3 illustrates a cross-section of an improved molded fiber, in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

In accordance with the present disclosure, methods and products are provided which solve deficiencies in the prior art pertaining to the availability of high quality molded fiber, particularly molded fiber used in packaging.

Lifted Fibers and Shedding

Most prior art molded fibers have a shedding problem caused by unfused fibers on the surface of molded fiber products, especially packaging products. Naturally white and colored base materials also have color fasting and shedding problems. The problem presents itself by particles dislodging from packaging during the handling and shipping.

In prior art molded fiber, after the fibers are formed together, the fibers go through a molding process in which two halves of the mold press the fibers into their final shape, using a heat (hot) press machine to apply heat and pressure. Shedding caused by loose unfused fibers on the surface of molded fiber peels off, or rubs off when rubbed against other materials or the same materials, causing unfused fibers to be dislodged from the surface becoming loose particles. The material which is dislodged floats in the product packaging or comes out when the package is opened. In some cases, if the actual product is packaged in a plastic bag or covering, the material shed is attracted by the static electricity to the bag and looks unprofessional when the product is opened.

FIG. 1 illustrates an improved molded fiber in accordance with embodiments of the present disclosure. As shown in FIG. 1, a light coat of paint binder or sealant 2, usually transparent, can be applied onto the surface of the molded fiber 1. A heat (hot) press can then be used to fuse the loose unfused fibers on the molded fiber 1. The sealant 2 can be natural, synthetic, oil base or biodegradable polymer (or a combination of these), as long as total non-biodegradability weight of the package is below 10% of total package weight. In one embodiment, Minwax® Sanding Sealer, which is designed to spray on natural products like wood can be used. In certain embodiments, the thickness of the sealant 2 is about 0.0001-0.0003 inches, which generally adds less than 1.0% to the total non-biodegradable amount by weight to the molded fiber 1. It is recommended to spray multiple coats of mist spray to achieve the about 0.0001 inch to 0.0003 inch thickness. Having a thicker sealant layer would not be expected to significantly reduce the shedding, and would needlessly increase the non-biodegradable percentage of total weight if a non-natural sealant is used.

There are at least two preferred process methods for applying the sealant 2, depending on whether the molded fiber 1 is prepressed or needs to be pressed. Molded fiber 1 which is not prepressed can be sprayed with a sealant, and then through the standard heat press process the surface fibers are fused together. Molded fiber 1 which has been prepressed is sprayed with the sealant 2 after the standard heat press process has already been applied, and then the molded fiber with the sealant is processed with another heat press process, fusing all surface fibers together after the second heat press. The first process method is the lower cost approach and is quicker because the second heat press step is not used. However, the second process method produces a higher quality molded fiber with the fibers being better fused than in the first process method.

The process method for molded fiber which is not prepressed involves the following steps:

-   -   1. Complete molded fiber creation process before heat press         process.     -   2. Spray a binder or sealant on the molded fiber and process         through the standard molded fiber heat press process     -   3. A person of ordinary skill in the art would understand that         the molded fiber heat press process should use between about 0.5         ton and 15 ton of pressure depending on the dimensions of the         molded fiber (i.e. its thickness, length and width) with         temperature ranging from 50° C. to 185° C.

The process method for molded fiber which is prepressed involves the following steps:

-   -   1. Complete molded fiber creation process after it is prepressed         (i.e, a first heat press process has been applied).     -   2. Spray a binder or sealant on the molded fiber and process         through the standard molded fiber heat press process again.     -   3. A person of ordinary skill in the art would understand that         the molded fiber heat press process should use between about 0.5         ton and 15 ton of pressure depending on the dimensions of the         molded fiber (i.e. its thickness, length and width) with         temperature ranging from 50° C. to 185° C.

In certain embodiments, about 0.0001 to 0.0003 inches of sealant is applied to a molded fiber which is not preprocessed. This molded fiber is about 4 millimeters thick and has a two-dimensional surface of about 12 by 9 inches. A 15 ton and 165° C. heat press process is then applied to the molded fiber with sealant to fuse the loose unfused fibers on the molded fiber.

In certain other embodiments, the sealant is applied to a molded fiber which is prepressed. The molded fiber is prepressed by applying a 15 ton and 165° C. heat press process. After this process, the prepressed molded fiber is about 1.74 millimeters thick and has a two-dimensional surface of about 12 by 9 inches. About 0.0001 to 0.0003 inches of sealant is then applied to the prepressed molded fiber. A 5 ton and 160° C. heat press process is then applied to the molded fiber with sealant to further fuse the loose unfused fibers on the molded fiber.

A suitable heat (hot) press machine for the molded fiber heat press process is the Xin Ming brand machine available from Shenzhen Xin Ming Machinery Co., Ltd. Another suitable heat (hot) press machine is the NANYA brand, model ZC140, with 20 ton working pressure and about 160 to 200° C. working temperature, available from Guangzhou Nanya Pulp Molding Equipment Co., Ltd.

Color Options

Currently, low cost molded fiber generally has a natural brown color and customers may require different colors to improve aesthetics. In the prior art, typically more expensive fiber based material must be used but that does not provide a multicolor option on the same products. White fiber can include, but is not limited to, A4 paper, bamboo, bagasse, a combination of bamboo and bagasse, wood, and paper foam which are all more expensive.

Embodiments of the present invention can use biodegradable or natural base paint to coat the surface of molded fiber and provide unlimited color options, including multiple colors on the same product. A standard spray process used for a water based paint is utilized to apply layers of paint on the surface of the molded fiber. Most of the biodegradable or natural paint dries quickly without requiring high temperature curing which saves time and money. The biodegradable paint can include, but is not limited to, natural material like marble flour, chalk, vegetable casein, kaolin, lime-hydrate, soda, methyl cellulose, linseed stand oil, tung stand oil, balsamic turpentine, zinc white, talcum, silicic acid, clay, quartz, lead-free drying agents (e.g., cobalt, zirconium, calcium, and manganese drying agents), pigments like titanium, iron oxide, nickel titanium, or animal and vegetable based material combined with natural material like natural clay fillers, caseins, sodium complexes and calcium hydroxide (Ca(OH)2).

In one preferred embodiment, Kreidenzeit™ natural paint and SafePaint™ organic milk paint can be used. FIG. 2 illustrates an improved molded fiber in accordance with embodiments of the present disclosure, which includes a paint layer 3 which has been applied on top of the sealant layer 2 of the molded fiber 1. After a sealant 2 is applied to the molded fiber 1 as described above, the biodegradable paint 3 can then be applied. In a preferred embodiment, the paint is applied at about 0.001 to 0.004 inches, dried thickness.

Biodegradable paint can be applied through an automated or a manual spray process, or a brush or rolling technique. Generally, higher quality paint results can be expected using a spray process.

Cracking

Biodegradable and natural paints do not have a lot of elasticity because of the nature of their natural chemistry, and this can result in cracking when the painted surface is flexed.

In one embodiment of the present invention, the problem of cracking can be eliminated or reduced by mixing a binder with the biodegradable or natural paint. Embodiments of the present invention can use less than about 10% of binder mixed with biodegradable or natural paint (e.g., a natural, synthetic or oil based binder). The mixture resolves or reduces the cracking problem and still keeps the total biodegradable based molded fiber material above 90% by weight. As discussed in more detail below, an additional benefit of a binder additive is the improvement of color fasting and reduction of shedding. In embodiments of the present invention, the preferred percentage of non-biodegradable material by weight in the package is less than 4%.

While adding a non-biodegradable binder improves the flexibility of the paint, it increases the percentage of the non-biodegradable material within the total weight of the product. The regulations for allowable non-biodegradable material vary from country to country and state to state. As understand by one of ordinary skill in the art, these varying regulations, as well as performance and additive amount need to be balanced to meet each specific market and product requirement.

In certain embodiments, Minwax® Sanding Sealer or ECOS Filler Sealer™ synthetic binders, at less than 5% total solid per paint volume, can be mixed with the paint to reduce cracking. In certain other embodiments, animal adhesive and glue products, like the ones provided by U.S. Adhesives, Inc. can be mixed with the paint. These later products are natural products that do not or minimally affect the biodegradability percentage of the total coating applied to the molded fiber, and so the percentage of these products mixed with the paint can be increased to about 10-15% of the total paint solid weight. However, even at those percentages, these natural products are believed to have lower performance at reducing or eliminating cracking versus the non-biodegradable additives.

Color Fasting

Natural white and natural colored molded fiber, which has not been painted, as well as molded fiber painted with biodegradable paint are prone to color fasting and shedding. Biodegradable paint is prone to these problems because of its lack of sufficient binder.

In an embodiment of the present invention, sealant can be applied to the surface of an unpainted, naturally white or naturally colored molded fiber. In an embodiment where the surface of the molded fiber is painted, such as disclosed herein, the sealant can be applied to the painted surface. In such an embodiment, the painted surface is painted with a biodegradable or natural paint that can, if so desired, be mixed with a binder or sealant before it is applied. In an embodiment where the surface of the molded fiber is not painted (e.g., it already has the desired color naturally), the sealant is applied and a heat press process, as described above in the Lifted Fibers And Shedding section, is applied either to a prepressed molded fiber or a molded fiber that has not been prepressed.

Application of sealant to the surface of a naturally white or naturally colored molded fiber, or to a painted surface of a molded fiber eliminates or reduces the color fasting and shedding problem. The final product will have a clean and plastic like feel to the consumer.

FIG. 3 illustrates an improved molded fiber in accordance with embodiments of the present disclosure, in which the molded fiber 1 includes a paint layer 3 which has been applied on top of the sealant 2. A sealant section 4 is then applied to the surface of the paint layer 3. The sealant section 4 can be applied by a spray misting process, and in one embodiment up to three sealant layers can be applied to comprise the sealant section. The sealant section can be natural, synthetic, oil base or biodegradable polymer (or a combination thereof), as long as total non-biodegradability weight of the package is below about 10% of total package weight.

In certain embodiments of the present invention, the sealant section is formed by spraying multiple coats of sealant onto the surface of the molded fiber, whether or not it is painted, using a mist spray process, to achieve a thickness of about 0.0001 to 0.0003 inches. A thicker sealant section will increases resistance to color fasting and shedding but also increase non-biodegradability of the total weight of the molded fiber package if natural sealant is not used.

It will be appreciated that details of the foregoing embodiments, given for purposes of illustration, are not to be construed as limiting the scope of the invention. Although several embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention, which is further defined in the converted utility application and appended claims. Further, it is recognized that many embodiments may be conceived that do not achieve all the advantages of some embodiments, particularly preferred embodiments, yet the absence of a particular advantage shall not be construed to necessarily mean that such an embodiment is outside the scope of the present invention. 

What is claimed is:
 1. A method for providing a high quality molded fiber product, the method comprising: providing a prepressed molded fiber which is biodegradable; applying a sealant to a top surface of the molded fiber to form a sealant layer; and applying a heat press process to the molded fiber and sealant layer.
 2. The method of claim 1, wherein the sealant is a natural, synthetic, oil based, or biodegradable polymer sealant, or a combination thereof.
 3. The method of claim 2, wherein the sealant layer adds less than 10% of total non-biodegradable weight to a total weight of the molded fiber product.
 4. The method of claim 1, further comprising applying a biodegradable paint to a top surface of the sealant layer after said heat press process.
 5. The method of claim 4, wherein the biodegradable paint is mixed with a natural, synthetic or oil based binder before the paint is applied.
 5. The method of claim 5, wherein the sealant layer and the paint mixed with a binder adds less than 10% of total non-biodegradable weight to a total weight of the molded fiber product.
 7. A method for providing a high quality molded fiber product, the method comprising: providing a molded fiber which is not prepressed and is biodegradable; applying a sealant to a top surface of the molded fiber to form a sealant layer; and applying a heat press process to the molded fiber and the sealant layer.
 8. The method of claim 7, wherein the sealant is a natural, synthetic, oil based, or biodegradable polymer sealant, or a combination thereof.
 9. The method of claim 8, wherein the sealant layer adds less than 10% of total non-biodegradable weight to a total weight of the molded fiber product.
 10. The method of claim 7, further comprising applying a biodegradable paint to a top surface of the sealant layer after said heat press process.
 11. The method of claim 10, wherein the biodegradable paint is mixed with a natural, synthetic or oil based binder before the paint is applied.
 11. The method of claim 11, wherein the sealant layer and the paint mixed with a binder adds less than 10% of total non-biodegradable weight to a total weight of the molded fiber product.
 13. A method for providing a high quality molded fiber product, the method comprising: providing a prepressed molded fiber which is biodegradable; applying a sealant to a top surface of the molded fiber to form a first sealant layer; applying a heat press process to the molded fiber and the first sealant layer; applying a biodegradable paint layer to a top surface of the first sealant layer after said heat press process; and applying a second sealant to a top surface of the biodegradable paint layer to form a second sealant layer.
 14. The method of claim 13, wherein the first and second sealants respectively comprise a natural, synthetic, oil based, or biodegradable polymer sealant, or a combination thereof.
 15. The method of claim 14, wherein the first sealant layer, paint layer, and second sealant layer add less than 10% of total non-biodegradable weight to the total weight of the molded fiber product.
 16. A method for providing a high quality molded fiber product, the method comprising: providing a molded fiber which is not prepressed and is biodegradable; applying a sealant to a top surface of the molded fiber to form a first sealant layer; applying a heat press process to the molded fiber and the first sealant layer; applying a biodegradable paint layer to a top surface of the first sealant layer after said heat press process; and applying a binder to a top surface of the biodegradable paint layer to form a second sealant layer.
 17. The method of claim 16, wherein the first and second sealants respectively comprise a natural, synthetic, oil based, or biodegradable polymer sealant, or a combination thereof.
 18. The method of claim 17, wherein the sealant layer, paint layer, and second sealant layer add less than 10% of total non-biodegradable weight to the total weight of the molded fiber product.
 19. A high quality molded fiber product comprising: a molded fiber which is biodegradable; a sealant layer on a top surface of the molded fiber; and wherein a heat press process was applied to the molded fiber and the sealant layer.
 20. A high quality molded fiber product comprising: a molded fiber which is biodegradable; a sealant layer on a top surface of the molded fiber, wherein a heat press process was applied to the molded fiber and the sealant layer; and a biodegradable paint layer on a top surface of the sealant layer.
 21. A high quality molded fiber product comprising: a molded fiber which is biodegradable; a first sealant layer on a top surface of the molded fiber, wherein a heat press process was applied to the molded fiber and the first sealant layer; a biodegradable paint layer on a top surface of the first sealant layer; and a second sealant layer on a top surface of the paint layer.
 22. The molded fiber of claim 21, wherein the first and second sealant layers respectively comprise a natural, synthetic, oil based, or biodegradable polymer sealant, or a combination thereof.
 23. The molded fiber of claim 21, wherein the biodegradable paint layer was premixed with a natural, synthetic or oil based binder.
 24. The molded fiber of claim 21, wherein the first sealant layer, the paint layer, and the second sealant layer add less than 10% of total non-biodegradable weight to the total weight of the molded fiber product.
 25. A high quality molded fiber product comprising: a molded fiber which is biodegradable; a first sealant layer on a top surface of the molded fiber, a biodegradable paint layer on a top surface of the first sealant layer; and a second sealant layer on a top surface of the paint layer.
 26. The molded fiber of claim 25, wherein the first sealant layer, the paint layer, and the second sealant layer add less than 10% of total non-biodegradable weight to the total weight of the molded fiber product. 